I am seeing this repeatedly. May be happening between updates. As in, I haven't worked on this file for a couple of weeks, installed the latest update, and now this is happening AGAIN. As in, I have seen this repeatedly in X8. I have also seen it when importing CAD from other sources as well.
But, the attached screen shots are (1) some text I placed a couple of weeks ago, and now come back to it and all over the place I have to re-size the text box to get the missing letter, or letters,